Thread tension device for loom shuttles



June 22, 1943.

r J. E. JOHNSON THREAD TENSION DEVICE FOR LOOM SI IUT'I'LES Filed March 12, 1942 oZhm/Mzwwm Patented June 22, 1943 THREAD TENSION DEVICE FGR Loom SHUTTLES- John Edward Johnson, Millbury, Mass, assignor to Watson-Williams Manufacturing Company, Millbury, Mass, a corporation of lllassachusetts Application March 12, 1942, Serial No. 434,415

2 Claims.

This invention relates to devices for regulating and controlling the tension on a weft thread as it is delivered from a loom shuttle. More specifically, my invention relates to the class of tension devices commonly termed zig-zag tensions.

It is one object of my invention to improve and simplify the construction of such tension devices by providing a single unitary fixed member in place of the plurality of fixed pins previously used. I also make special provision to effectively protect said unitary device from wear.

A further object of my invention is to provide improved means for actuating the movable thread-tensioning member.

My invention further relates to certain arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of the invention is shown in the drawing, in which Fig. 1 is a partial sectional plan view of a shuttle embodying my improvements;

Fig. 2 is a partial side elevation, looking in the direction of the arrow 2 in Fig. 1;

Fig. 3 is a planview of the fixed unitary device which replaces the usual fixed tension pins;

Figs. 4 and 5 are front and rear elevations thereof, looking in the direction of the arrows 4 and 5 in Fig. 3;

Fig. 6 is an end elevation, looking in. the direction of the arrow 6 in Fig. 3;

Fig. 7 is a detail side elevation, looking in the direction of the arrow 1 in Fig. 1;

Fig. 8 is a detail view of a tension spring and stud; and

Fig. 9 is an enlarged sectional plan View, taken substantially along the line 9-9 in Fig. 4.

Referring to the drawing, I have shown a portion of a shuttle S having the usual opening It in the body portion to receive a bobbin B on which is wound a weft thread T. The shuttle S also has a horizontal recess l2 in its front end portion, to which recess the thread is delivered through a porcelain guide bushing M at the front end of the body opening Ill.

A thread tension device of the zig-zag type is mounted in the horizontal recess l2 and comprises a movabl tension member 20 andv a fixed guide member 2|. The fixed guide member is of U-shaped cross section, as shown in Fig. 6, and is preferably formed from a single piece of relatively thin sheet metal, pressed and bent to the form shown in Figs. 3 to 6. The fixed member 2| comprises a top plate 23, a bottom plate 24, a front end portion 25, a plurality of front spacing strips 26 separated by openings 21, and an end strip 28.

In the preferred construction, the entire front face of the member 2| is provided with a thin coating 39 of porcelain or enamel, which also extends around the side edges adjacent the openings 21. This smooth and hard coating reduces wear and also prevents cutting of the thread on sharp metal edges.

The device 2| fits snugly into the horizontal recess l2, as shown in Figs. 1 and 2, and is retained in fixed position by screws 32 and 33. The movable tension member 20 is pivotally mounted between the top plate 23 and the bottom plate 24 0f the fixed member 2|, and is mounted to swing on the screw or stud 33 which also acts to hold the fixed member 2| in position.

The movable tension member 20 has a plurality of loops 35 through which the thread T is passed, and the thread is also looped around the spacing strips 26 of the member 2|. The normal position of the loops 35 is shown in full lines in Fig. 1, and the positions to which the loops may move to relieve excessive tension are indicated in dotted lines in Fig. 1.

The movable tension member 20 is preferably of wire construction, as shown in Fig. 7, with a closely coiled bearing portion 36 and with a laterally extending arm 31, which is preferably fiatltened and bent to provide an opening 38.

My improved means for actuating the movable member 20 comprises a loosely coiled spring 413 made of fine wire and welded or otherwise secured to a stud 4| having a slotted head 42. The spring 49 preferably has a substantially straight and outwardly extending end portion 43.

The spring 4|], stud 4|, and head 42 fit snugly in corresponding recesses 50 and 5| in the body of the shuttle S, as clearly shown in Fig. 1. The parts are so fitted that the stud and spring may be rotated by use of a screw-driver but will otherwise be held from angular movement or axial displacement by friction.

In order to assemble the parts, the members 2|) and 2| are mounted in the recess l2, after which the spring All and stud 4| are inserted in the recesses 5i! and 5| and are pushed and turned until the projecting end portion 43 of the spring enters the opening 38 (Fig. 7) in the arm 31 of the member 20. Further rotation of the stud 4| and spring 40 will thread the spring through the arm 31 and will increase the tension on the arm as the stud and spring are further rotated. v I

I thus provide a very light and delicate tension for the movable member 20, which tension may be very conveniently adjusted by turning the stud 4| in one direction or the other. The spring 40 is preferably made of brass.

A thread tension device constructed as above described is simple and economical to manufacture, easy to adjust, and reliable and satisfactory in use.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is:

1. A thread tension device in a loom shuttle comprising fixed and pivoted guide and tension members, said pivoted member having an arm with an opening therein, and a light loosely head and rotatably mounted in said shuttle, said spring being threaded in said arm through said .opening and being adjustabl by rotation to vary the tension of said movable member on the thread.

JOHN EDWARD JOHNSON. 

